There has been known an outdoor unit for an air-conditioning apparatus including a fin-tube heat exchanger mounted thereto. One such heat exchanger includes a flat tube having a sectional shape of a rectangle with rounded corners. The heat exchanger using the flat tube is herein referred to as “flat-tube heat exchanger”.
There has been known a flat-tube heat exchanger having the following configuration. That is, U-shaped cutouts are formed in each of fins so as to extend in a width direction from one end of the fin in the width direction, and flat tubes are fitted to the cutouts. In the flat-tube heat exchanger, heat transfer tubes are each formed by bending one flat tube into a U shape. The flat-tube heat exchanger includes a plurality of heat exchange portions. In each of the heat exchange portions, a plurality of flat tubes are arrayed so that longitudinal directions of the elongate shapes are aligned, and the fins are connected to the flat tubes so as to be arrayed with a plurality of predetermined gaps. When seen in a direction along a longitudinal direction of the fins, the flat-tube heat exchanger is typically bent into an L shape or a substantially U shape.
When heat exchangers using flat tubes having the same length are arrayed in a plurality of rows and bent into the L shape, a heat exchanger provided at a position on an outer side of the L-shaped bent part has a bend radius that is different from a bend radius of a heat exchanger provided at a position on an inner side of the L-shaped bent part have different. Therefore, the heat exchanger provided on the inner side of the bent part and the heat exchanger provided on the outer side of the bent part are not aligned at positions of U-shaped bent portions being one end portions of the heat exchangers (hereinafter also referred to as “hairpin portion”) or at positions of header connection portions being other end portions. In a heat exchanger of Patent Literature 1, a plurality of rows of heat exchange portions are arrayed with hairpin portions being aligned, the hairpin portions being one end portions.